Q: How Can I Tell If My Car Battery Needs Replacing?

A battery needs to be replaced when it can no longer support the electrical and starting system of the vehicle. How will you know this? The most common first signs that a battery is starting to go bad may not be obvious at first. You may start to see an intermittent dim in your lights when you turn on an electrical system like an AC blower or interior light when you are at idle. Your radio light may dim when the AC compressor cycles on and off. These may be some first signs your battery is getting weak.

As your battery ages, it uses up its internal battery lead plates and will get weaker as time goes by. Depending on the make and model of battery you have, it may last anywhere from two years to five or six. Most batteries will last about three years or more. Even though they last this long, they will get weaker over time and if you are pushing the battery and charging to the limits of its capacity now, it may not last too much longer before showing major signs of needing replacement.

The major signs of a battery needing replacement is excessive corrosion buildup on top of the battery and its posts. After this, you will have a slow cranking engine during startup. Then you may notice intermittent no-crank conditions and have to jumpstart the vehicle after it sits for a couple of days. It cannot hold a charge for that long of a period.

Once you start to have these kind of problems you will need to have the battery replaced and the cables serviced. If you do not and continue to drive it this way you will start to put a bigger and bigger strain on the alternator. This in turn will cause the alternator to fail and then you will have a battery and alternator to replace. Once the battery is replaced and the cables replaced or cleaned as needed, the charging system should be tested to make sure there has been no damage to it. The alternator will need to have a good battery to be properly tested.